Infectious etiologic agent detection probe and probe set, carrier, and genetic screening method

ABSTRACT

An infectious etiologic agent detection probe set which detects an infectious etiologic agent gene, includes a plurality of kinds of probes including oligonucleotide having base sequences selected from each of a plurality of groups selected from a first group including base sequences of SEQ ID Nos. 1 to 14 and complementary sequences thereof, a second group including base sequences of SEQ ID Nos. 15 to 24 and complementary sequences thereof, a third group including base sequences of SEQ ID Nos. 25 to 36 and complementary sequences thereof, a fourth group including base sequences of SEQ ID Nos. 37 to 47 and complementary sequences thereof, a fifth group including base sequences of SEQ ID Nos. 48 to 57 and complementary sequences thereof, a sixth group including base sequences of SEQ ID Nos. 58 to 68 and complementary sequences thereof, a seventh group including base sequences of SEQ ID Nos. 69 to 77 and complementary sequences thereof, an eighth group including base sequences of SEQ ID Nos. 78 to 85 and complementary sequences thereof, a ninth group including base sequences of SEQ ID Nos. 86 to 97 and complementary sequences thereof, and a 10th group including base sequences of SEQ ID Nos. 98 to 106 and complementary sequences thereof.

FIELD OF THE INVENTION

The present invention relates to detection and/or identification of an infectious etiologic agent as an etiologic agent of an infectious disease and, more particularly, to a probe and probe set originated in an infectious etiologic agent, a carrier, and a genetic screening method, which are useful for detection and identification of the etiologic agent of an infectious disease.

The present invention also relates to a PCR amplification process of an infectious etiologic agent, which is suitable for detection and/or identification of an infectious etiologic agent.

BACKGROUND OF THE INVENTION

In recent years, gene expression analysis using DNA chips (also referred to as DNA microarrays hereinafter) is done in various fields including drug development. Different specimen DNAs are made to react with a DNA microarray in which various kinds of gene sets (probes) are arranged. Gene dosages which exist in the respective specimens are compared. Genes which are present in high dosages (the expression amounts are large) or inactive genes (the expression amounts are small) at each stage are classified and analyzed in association with functions.

An example is an infectious etiologic agent test. In Japanese Patent Laid-Open No. 2001-299396, Ezaki et al have proposed a microorganism identification method using, as a DNA probe, a DNA chip on which chromosome DNAs are immobilized. According to this method, a plurality of chromosome DNAs originated in a plurality of known microorganisms with different GC contents are made to react with chromosome DNAs originated in an unknown microorganism in a specimen. When the resultant hybridization complex is detected, the unknown microorganism in the specimen can be detected.

As probes used for DNA chips for infectious etiologic agent tests, Ono et al have proposed a bacterial detection probe using restriction enzyme fragments in Japanese Patent Laid-Open No. 6-133798, a Pseudomonas aeruginosa detection probe in Japanese Patent Laid-Open No. 10-304896, and a detection probe using restriction enzyme fragments of Escherichia coli, klebsiella pneumoniae, and Enterobacter cloacae in Japanese Patent Laid-Open No. 10-304897.

As a microarray, for example, a microarray using stamping called a Stanford method is known. For example, DNA chips on which cDNA fragments of known genes of human origin, which are related to cancers, are applied by spotting or stamping and chips prepared by bonding cDNA fragments of 1,000 kinds of known genes of human origin to slide glasses are commercially available from TAKARA SHUZO.

On the other hand, a chip available from Affymetrix is prepared by designing an oligonucleotide probe set on the basis of the known gene cDNAs, and probes are laid out by synthesis on a substrate. Oligoprobes are laid out on one chip at a high density so that the expression levels of 10,000 or more genes can be analyzed at once.

However, the DNA chips of the prior arts described above use DNA probes such as chromosome DNAs or restriction enzyme fragments. DNAs directly extracted from microorganisms are used as materials. For this reason, the chips can hardly be mass-prepared at a time and are not suitable for clinical diagnosis. For application to clinical diagnosis, mass production of inexpensive and uniform DNA chips is necessary. For this purpose, mass preparation of uniform DNAs as probe solutions is essential. However, mass preparation of DNA probes is impossible. Even for DNA probes, when PCR amplification reaction is used, the number of DNAs can gradually be increased. However, mass preparation at a time using the PCR reaction is difficult, and the DNA chips are difficult to use for clinical diagnosis.

In addition, since the base length of a DNA probe is large, it is difficult to identify one species in similar species. Such a DNA probe is therefore not suitable for, e.g., infection detection. In treating an infection, the species must be specified, and antibiotic drugs corresponding to it must be selected and administered. For this purpose, an infection detection probe is required to have a function capable of detecting a species while discriminating similar species, although bacteria belonging to the same species need not accurately be discriminated (that is, bacteria in the same species can be detected all together). However, in, e.g., the DNA chip using restriction enzyme fragments of Escherichia coli, klebsiella pneumoniae, and Enterobacter cloacae, which is disclosed in Japanese Patent Laid-Open No. 10-304897, cross reaction occurs between the three species because of the large base length of the probe. Since similar species cannot individually be discriminated, the DNA chip can hardly be used for infection detection.

As an application purpose of microarrays, infectious etiologic agent tests have received a great deal of attention. Some probe sets aiming at testing infectious etiologic agents have also been proposed.

As an important point of bacterial tests using microarrays, detection must be possible even when the number of infectious etiologic agents is small. To do this, it is effective to amplify specific parts in the base sequences of the DNAs of infectious etiologic agents by, e.g., PCR reaction using primers. For example, a 16s rRNA gene arrangement contains a sequence unique to the species in the information of about 1,700 base pairs. When the sequence is used, classification can be done to some extent. In detecting/identifying bacteria, 16s rRNA parts in the DNA base sequences of bacteria are preferably used. Hence, it is demanded to amplify the 16s rRNA parts.

For various kinds of bacteria, however, the gene arrangements are only partially clarified, and the 16s rRNAs are not totally known. For this reason, it is not easy to design primers for PCR amplification reaction.

SUMMARY OF THE INVENTION

The present invention has been made in consideration of the above situation, and has as its object to provide an infection detection probe which allows mass preparation at a time and identification of a species in similar species.

More specifically, it is an object of the present invention to provide an infection detection probe which can suitably be used to classify a plurality of kinds of etiologic agents of an infection on the basis of the species.

It is another object of the present invention to provide a probe set which also considers the stability of a hybrid body between an infection detection probe and a specimen so that the difference between similar species can accurately be evaluated on a DNA chip.

It is still another object of the present invention to provide a carrier on which the infection detection probe is immobilized to make the infection detection probe react with the specimen.

It is still another object of the present invention to provide a carrier on which the infection detection probes are chemically immobilized so that the infection detection probes are stably immobilized on the carrier, and a detection result with high reproducibility can be obtained in the process of reaction with a specimen solution.

It is still another object of the present invention to provide a PCR reaction primer which amplifies the 16s rRNAs of an etiologic agent in a specimen in order to detect and/or identify an infectious etiologic agent.

It is still another object of the present invention to provide a primer set which can commonly be used for a plurality of species and effectively amplify the 16s rRNAs of an etiologic agent even when the species is unknown.

It is still another object of the present invention to provide a primer set which can amplify the 16s rRNAs of a plurality of kinds of etiologic agents under the same PCR conditions.

The present invention provides a primer set characterized by amplifying all species without amplifying genes originated in human genomes by causing PCR reaction for a human blood specimen by using all the primer sets simultaneously. More specifically, a primer set having a sequence which is different from the base sequence of human genome genes by three or more bases is proposed.

Other features and advantages of the present invention will be apparent from the following description.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

A preferred embodiment of the present invention will now be described in.

In the following embodiment, an oligonucleotide probe used to identify the etiologic agent of an infection and, more specifically, a probe used to detect one or some of Staphylococcus aureus, Staphylococcus epidermidis, Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Serratia marcescens, Streptococcus pneumoniae, Haemophilus influenzae, Enterobacter cloacae, and Enterococcus faecalis will be described. That is, a nucleic acid probe or nucleic acid probe set, which is used to detect rRNA gene arrangements in the genes of the above 10 infectious etiologic agents in proper quantities, is disclosed.

According to this embodiment, the oligonucleotide probe to be reacted with a specimen solution containing the nucleic acid sequence of the genes of the infectious etiologic agents contains one base sequence which belongs to one of the first group (SEQ ID Nos. 1 to 14 in the attached sequence table) shown in Table 1, the second group (SEQ ID Nos. 15 to 24) shown in Table 2, the third group (SEQ ID Nos. 25 to 36) shown in Table 3, the fourth group (SEQ ID Nos. 37 to 47) shown in Table 4, the fifth group (SEQ ID Nos. 48 to 57) shown in Table 5, the sixth group (SEQ ID Nos. 58 to 68) shown in Table 6, the seventh group (SEQ ID Nos. 69 to 77) shown in Table 7, the eighth group (SEQ ID Nos. 78 to 85) shown in Table 8, the ninth group (SEQ ID Nos. 86 to 97) shown in Table 9, and the 10th group (SEQ ID Nos. 98 to 106) shown in Table 10 (to be described later). An oligonucleotide probe having a base sequence selected from the first group detects Staphylococcus aureus. An oligonucleotide probe having a base sequence selected from the second group detects Staphylococcus epidermidis. An oligonucleotide probe having a base sequence selected from the third group detects Escherichia coli. An oligonucleotide probe having a base sequence selected from the fourth group detects Klebsiella pneumoniae. An oligonucleotide probe having a base sequence selected from the fifth group detects Pseudomonas aeruginosa. An oligonucleotide probe having a base sequence selected from the sixth group detects Serratia marcescens. An oligonucleotide probe having a base sequence selected from the seventh group detects Streptococcus pneumoniae. An oligonucleotide probe having a base sequence selected from the eighth group detects Haemophilus influenzae. An oligonucleotide probe having a base sequence selected from the ninth group detects Enterobacter cloacae. An oligonucleotide probe having a base sequence selected from the 10th group detects Enterococcus faecalis.

Complementary sequences of these probe sequences can also be used as effective probe sequences because they have the same functions as those of the above probe sequences (the complementary sequences of the first group are indicated by SEQ ID Nos. 113 to 126 in the attached sequence table, the complementary sequences of the second group are indicated by SEQ ID Nos. 127 to 136, the complementary sequences of the third group are indicated by SEQ ID Nos. 137 to 148, the complementary sequences of the fourth group are indicated by SEQ ID Nos. 149 to 159, the complementary sequences of the fifth group are indicated by SEQ ID Nos. 160 to 169, the complementary sequences of the sixth group are indicated by SEQ ID Nos. 170 to 180, the complementary sequences of the seventh group are indicated by SEQ ID Nos. 181 to 189, the complementary sequences of the eighth group are indicated by SEQ ID Nos. 190 to 197, the complementary sequences of the ninth group are indicated by SEQ ID Nos. 198 to 209, and the complementary sequences of the 10th group are indicated by SEQ ID Nos. 210 to 218).

The probes for the respective bacteria were designed from the genome parts coding the 16s rRNAs such that they could have a very high specificity with respect to the corresponding bacteria, any variation between the probe base sequences could be prevented, and a sufficient hybridization sensitivity could be expected.

These oligonucleotide probes are designed such that a stable hybrid body is formed by hybridization reaction between a specimen and two or more kinds of probes bonded onto a carrier, and a satisfactory result can be obtained.

As a characteristic feature, the carrier according to the present invention, on which the infection detection probe of the present invention is immobilized, is prepared by discharging oligonucleotide by using a BJ printer and chemically bonding it to the carrier. As compared to the prior arts, the probe hardly peels off. An additional effect for increasing the sensitivity is also obtained. When a DNA chip is produced by stamping called a Stanford method that is generally widely used (for example, TAKARA SHUZO produces DNA chips by applying cDNA fragments of known genes of human origin, which are related to cancers, by spotting or stamping), the applied DNA readily peels off. In addition, when a probe is laid out on a DNA chip by synthesis, as in the prior art (e.g., the DNA chip available from Affymetrix), accurate evaluation is impossible because the synthesis yield changes between probe sequences. The carrier according to the present invention is prepared also in consideration of these problems. As its characteristic features, the probe is stably immobilized and hardly peels off, as compared to the prior arts, and highly sensitive and accurate detection can be executed. The preferred embodiment of the present invention will be described below in detail.

The DNA chip of this embodiment can be applied to any specimen in which bacteria may be present, and for example, body fluids originated in animals such as human and livestock, including blood, spinal fluid, phlegm, stomach fluid, vaginal discharge, and intraoral mucus, and excretion such as urine and feces. All media which can be contaminated by bacteria can also be subjected to a test using the DNA chip, including food, drink water and hot spring water in the natural environment, which may cause food poisoning by contamination, filters from air and water cleaners, and so forth. Animals and plants which should be quarantined in import/export are also used as specimens.

The specimens used for the DNA chip of this embodiment include not only an extracted nucleic acid itself but also specimens prepared by various methods, such as an amplified specimen prepared by using an PCR reaction primer designed for 16s rRNA detection, a specimen prepared by causing PCR reaction on the basis of a PCR amplified product, a specimen prepared by an amplification method other than PCR, and a specimen labeled by various labeling methods for visualization.

The carrier used for the DNA chip of this embodiment includes all sorts of carriers including flat substrates such as a glass substrate, a plastic substrate, and a silicon wafer, a three-dimensional structure having a three-dimensional pattern, a spherical body such as a bead, and rod-, cord-, and thread-shaped structures. The carrier also includes a substrate whose surface is processed such that a probe DNA can be immobilized. Especially, a carrier prepared by introducing a functional group to its surface to make chemical reaction possible has a preferable form from the viewpoint of reproducibility because the probe is stably bonded in the process of hybridization reaction.

As an example of the immobilization method used in the present invention, a combination of a maleimide group and a thiol (—SH) group is used. More specifically, a thiol (—SH) group is bonded to the terminal of a nucleic acid probe, and a process is executed make the solid surface have a maleimide group. Accordingly, the thiol group of the nucleic acid probe supplied to the solid surface reacts with the maleimide group on the solid surface to immobilize the nucleic acid probe.

To introduce the maleimide group, first, an aminosilane coupling agent is caused to react on a glass substrate. Next, the maleimide group is introduced by reaction between the amino group and an EMCS reagent (N-(6-Maleimidocaproyloxy)succinimide: available from Dojin). Introduction of the SH group to a DNA can be done by using 5′-Thiol-ModifierC6 (available from Glen Research) when the DNA is synthesized by an automatic DNA synthesizer.

Instead of the above-described combination of a thiol group and a maleimide group, a combination of, e.g., an epoxy group (in the solid phase) and an amino group (nucleic acid probe terminal) can also be used as a combination of functional groups to be used for immobilization. Surface treatments using various kinds of silane coupling agents are also effective. Oligonucleotide in which a functional group which can react with a functional group introduced by a silane coupling agent is introduced is used. A method of applying a resin having a functional group can also be used.

The present invention will be described below in more detail on the basis of examples using the infectious etiologic agent detection probes to be used to detect the 10 etiologic agents described above.

Example 1 Microorganism Detection Using 1-Step PCR 1. Preparation of Probe DNAs

Nucleic acid sequences shown in Tables 1 to 10 were designed as probes to be used for detection of the 10 etiologic agents. More specifically, the following probe base sequences were selected from the genome parts coding the 16s rRNAs of the respective bacteria. These probe base sequences were designed such that they could have a very high specificity with respect to the corresponding bacteria, any variation between the probe base sequences could be prevented, and a sufficient hybridization sensitivity could be expected (The probe base sequences need not always completely match those shown in Tables 1 to 10. Probe base sequences having base lengths of 20 to 30, including the probe base sequences, are also included in the probe base sequence shown in the tables. As described above, complementary sequences (complementary strands) of the base sequences shown in the tables may also be used).

In the following tables, “Probe No.” is assigned for convenience. SEQ ID Nos. coincide with those in the attached sequence tables. As described above, the complementary strand sequences of the base sequences with SEQ ID Nos. 1 to 106 have SEQ ID Nos. 113 to 218.

TABLE 1 Probes for detecting Staphylococcus aureus strain Name of Probe SEQ ID microorganizm No. No. Sequence Staphylococcus PA-1 1 5′ GAACCGCATGGTTCAAAAGTGAAAGA 3′ aureus PA-2 2 5′ CACTTATAGATGGATCCGCGCTGC 3′ PA-3 3 5′ TGCACATCTTGACGGTACCTAATCAG 3′ PA-4 4 5′ CCCCTTAGTGCTGCAGCTAACG 3′ PA-5 5 5′ AATACAAAGGGCAGCGAAACCGC 3′ PA-6 6 5′ CCGGTGGAGTAACCTTTTAGGAGCT 3′ PA-7 7 5′ TAACCTTTTAGGAGCTAGCCGTCGA 3′ PA-8 8 5′ TTTAGGAGCTAGCCGTCGAAGGT 3′ PA-9 9 5′ TAGCCGTCGAAGGTGGGACAAAT 3′ PA-10 10 5′ ACGGACGAGAAGCTTGCTTCTCT 3′ PA-11 11 5′ TGTCACTTATAGATGGATCCGCGCT 3′ PA-12 12 5′ TGTAAGTAACTGTGCACATCTTGACG 3′ PA-13 13 5′ ACAACTCTAGAGATAGAGCCTTCCCC 3′ PA-14 14 5′ GTGGAGTAACCTTTTAGGAGCTAGCC 3′

TABLE 2 Probes for detecting Staphylococcus epidermidis strain Name of Probe SEQ ID microorganizm No. No. Sequence Staphylococcus PB-1 15 5′ GAACAGACGAGGAGCTTGCTCC 3′ epidermidis PB-2 16 5′ TAGTGAAAGACGGTTTTGCTGTCACT 3′ PB-3 17 5′ TAAGTAACTATGCACGTCTTGACGGT 3′ PB-4 18 5′ GACCCCTCTAGAGATAGAGTTTTCCC 3′ PB-5 19 5′ AGTAACCATTTGGAGCTAGCCGTC 3′ PB-6 20 5′ GAGCTTGCTCCTCTGACGTTAGC 3′ PB-7 21 5′ AGCCGGTGGAGTAACCATTTGG 3′ PB-8 22 5′ AGACGAGGAGCTTGCTCCTCTG 3′ PB-9 23 5′ AGAACAAATGTGTAAGTAACTATGCACGT 3′ PB-10 24 5′ ACCATTTGGAGCTAGCCGTCGA 3′

TABLE 3 Probes for detecting Escherichia coli strain Name of Probe SEQ ID microorganizm No. No. Sequence Escherichia PC-1 25 5′ CTCTTGCCATCGGATGTGCCCA 3′ coli PC-2 26 5′ ATACCTTTGCTCATTGACGTTACCCG 3′ PC-3 27 5′ TTTGCTCATTGACGTTACCCGCAG 3′ PC-4 28 5′ ACTGGCAAGCTTGAGTCTCGTAGA 3′ PC-5 29 5′ ATACAAAGAGAAGCGACCTCGCG 3′ PC-6 30 5′ CGGACCTCATAAAGTGCGTCGTAGT 3′ PC-7 31 5′ GCGGGGAGGAAGGGAGTAAAGTTAAT 3′ PC-8 32 5′ TAACAGGAAGAAGCTTGCTTCTTTGCTG 3′ PC-9 33 5′ TTGCCATCGGATGTGCCCAGAT 3′ PC-10 34 5′ GGAAGGGAGTAAAGTTAATACCTTTGCTC 3′ PC-11 35 5′ ATCTTTTGTTGCCAGCGGTCCG 3′ PC-12 36 5′ AAGGGAGTAAAGTTAATACCTTTGCTCATTG 3′

TABLE 4 Probes for detecting Klebsiella pneumoniae strain Name of Probe SEQ ID microorganizm No. No. Sequence Klebsiella PD-1 37 5′ TAGCACAGAGAGCTTGCTCTCGG 3′ pneumoniae PD-2 38 5′ TCATGCCATCAGATGTGCCCAGA 3′ PD-3 39 5′ CGGGGAGGAAGGCGATAAGGTTAAT 3′ PD-4 40 5′ TTCGATTGACGTTACCCGCAGAAGA 3′ PD-5 41 5′ GGTCTGTCAAGTCGGATGTGAAATCC 3′ PD-6 42 5′ GCAGGCTAGAGTCTTGTAGAGGGG 3′ PD-7 43 5′ TCATGCCATCAGATGTGCCCAGAT 3′ PD-8 44 5′ CGGGGAGGAAGGCGATAAGGTTAA 3′ PD-9 45 5′ TTATCGATTGACGTTACCCGCAGAAGA 3′ PD-10 46 5′ CATTCGAAACTGGCAGGCTAGAGTC 3′ PD-11 47 5′ CCTTTGTTGCCAGCGGTTAGGC 3′

TABLE 5 Probes for detecting Pseudomonas aeruginosa strain Name of Probe SEQ ID microorganizm No. No. Sequence Pseudomonas PE-1 48 5′ TGAGGGAGAAAGTGGGGGATCTTC 3′ aeruginosa PE-2 49 5′ TCAGATGAGCCTAGGTCGGATTAGC 3′ PE-3 50 5′ GAGCTAGAGTACGGTAGAGGGTGG 3′ PE-4 51 5′ GTACGGTAGAGGGTGGTGGAATTT 3′ PE-5 52 5′ GACCACCTGGACTGATACTGACAC 3′ PE-6 53 5′ TGGCCTTGACATGCTGAGAACTTTC 3′ PE-7 54 5′ TTAGTTACCAGCACCTCGGGTGG 3′ PE-8 55 5′ TAGTCTAACCGCAAGGGGGACG 3′ PE-9 56 5′ TGCATCCAAAACTACTGAGCTAGAGTAC 3′ PE-10 57 5′ GTCGACTAGCCGTTGGGATCCT 3′

TABLE 6 Probes for detecting Serratia marcescens strain Name of Probe SEQ ID microorganizm No. No. Sequence Serratia PF-1 58 5′ TAGCACAGGGAGCTTGCTCCCT 3′ marcescens PF-2 59 5′ AGGTGGTGAGCTTAATACGCTCATC 3′ PF-3 60 5′ TCATCAATTGACGTTACTCGCAGAAG 3′ PF-4 61 5′ ACTGCATTTGAAACTGGCAAGCTAGA 3′ PF-5 62 5′ TTATCCTTTGTTGCAGCTTCGGCC 3′ PF-6 63 5′ ACTTTCAGCGAGGAGGAAGGTGG 3′ PF-7 64 5′ GGTAGCACAGGGGAGCTTGCTC 3′ PF-8 65 5′ CGAGGAGGAAGGTGGTGAGCTTAATA 3′ PF-9 66 5′ TACGCTCATCAATTGACGTTACTCGC 3′ PF-10 67 5′ GAAACTGGCAAGCTAGAGTCTCGTAGA 3′ PF-11 68 5′ TTATCCTTTGTTGCCAGCGGTTCG 3′

TABLE 7 Probes for detecting Streptococcus pneumoniae strain Name of Probe SEQ ID microorganizm No. No. Sequence Streptococcus PG-1 69 5′ AGTAGAACGCTGAAGGAGGAGCTTG 3′ pneumoniae PG-2 70 5′ CTTGCATCACTACCAGATGGACCTG 3′ PG-3 71 5′ TGAGAGTGGAAAGTTCACACTGTGAC 3′ PG-4 72 5′ GCTGTGGCTTAACCATAGTAGGCTTT 3′ PG-5 73 5′ AAGCGGCTCTCTGGCTTGTAACT 3′ PG-6 74 5′ TAGACCCTTTCCGGGGTTTAGTGC 3′ PG-7 75 5′ GACGGCAAGCTAATCTCTTAAAGCCA 3′ PG-8 76 5′ GACATTTGCTTAAAAGGTGCACTTGCA 3′ PG-9 77 5′ GTTGTAAGAGAAGAACGAGTGTGAGAGTG 3′

TABLE 8 Probes for detecting Haemophilus influenzae strain Name of Probe SEQ ID microorganizm No. No. Sequence Haemophilus PH-1 78 5′ GCTTGGGAATCTGGCTTATGGAGG 3′ influenzae PH-2 79 5′ TGCCATAGGATGAGCCCAAGTGG 3′ PH-3 80 5′ CTTGGGAATGTACTGACGCTCATGTG 3′ PH-4 81 5′ GGATTGGGCTTAGAGCTTGGTGC 3′ PH-5 82 5′ TACAGAGGGAAGCGAAGCTGCG 3′ PH-6 83 5′ GGCGTTTACCACGGTATGATTCATGA 3′ PH-7 84 5′ AATGCCTACCAAGCCTGCGATCT 3′ PH-8 85 5′ TATCGGAAGATGAAAGTGCGGGACT 3′

TABLE 9 Probes for detecting Enterobacter Cloacae strain Name of Probe SEQ ID microorganizm No. No. Sequence Enterobacter PI-1 86 5′ CAGAGAGCTTGCTCTCGGGTGA 3′ Cloacae PI-2 87 5′ GGGAGGAAGGTGTTGTGGTTAATAAC 3′ PI-3 88 5′ GGTGTTGTGGTTAATAACCACAGCAA 3′ PI-4 89 5′ GCGGTCTGTCAAGTCGGATGTG 3′ PI-5 90 5′ ATTCGAAACTGGCAGGCTAGAGTCT 3′ PI-6 91 5′ TAACCACAGCAATTGACGTTACCCG 3′ PI-7 92 5′ GCAATTGACGTTACCCGCAGAAGA 3′ PI-8 93 5′ GTAGCACAGAGAGCTTGCTCTCG 3′ PI-9 94 5′ CGGGGAGGAAGGTGTTGTGGTTA 3′ PI-10 95 5′ ACCACAGCAATTGACGTTACCCG 3′ PI-11 96 5′ GAAACTGGCAGGCTAGAGTCTTGTAG 3′ PI-12 97 5′ AGGCGGTCTGTCAAGTCGGATG 3′

TABLE 10 Probes for detecting Enterococcus faecalis strain Name of Probe SEQ ID microorganizm No. No. Sequence Enterococcus PJ-1 98 5′ TTCTTTCCTCCCGAGTGCTTGCA 3′ faecalis PJ-2 99 5′ AACACGTGGGTAACCTACCCATCAG 3′ PJ-3 100 5′ ATGGCATAAGAGTGAAAGGCGCTT 3′ PJ-4 101 5′ GACCCGCGGTGCATTAGCTAGT 3′ PJ-5 102 5′ GGACGTTAGTAACTGAACGTCCCCT 3′ PJ-6 103 5′ CTCAACCGGGGAGGGTCATTGG 3′ PJ-7 104 5′ TTGGAGGGTTTCCGCCCTTCAG 3′ PJ-8 105 5′ ATAGAGCTTTCCCTTCGGGGACAAA 3′ PJ-9 106 5′ CGAGGTCATGCAAATCTCTTAAAGCTTCT 3′

For each probe shown in the tables, as a functional group to immobilize the probe to a DNA microarray, a thiol group was introduced to the 5′ terminal of the nucleic acid after synthesis in accordance with a conventional method. After introduction of the functional group, purification and freeze-drying were executed. The freeze-dried probes were stored in a freezer at −30° C.

2. Preparation of Specimen Amplification PCR Primers

As 16s rRNA gene (target gene) amplification PCR primers for etiologic agent detection, nucleic acid sequences shown in Table 11 were designed. More specifically, probe sets which specifically amplify the genome parts coding the 16s rRNAs, i.e., primers for which the specific melting points were made uniform as much as possible at the two end portions of the 16s rRNA coding region of a base length of 1,400 to 1,700 were designed. In order to simultaneously amplify variants or a plurality of 16s rRNA coding regions on genomes, a plurality of kinds of primers were designed. Note that a primer set is not limited to primer sets shown in the table 11. A primer set which is available in common to a plural kinds of etiologic agents and amplify almost entire length of 16s rRNA coding region of the etiologic agents can also be employed.

TABLE 11 Primer SEQ No. ID No. Sequence Forward F-1 107 5′ GCGGCGTGCCTAATACATGCAAG 3′ Primer F-2 108 5′ GCGGCAGGCCTAACACATGCAAG 3′ F-3 109 5′ GCGGCAGGCTTAACACATGCAAG 3′ Reverse R-1 110 5′ ATCCAGCCGCACCTTCCGATAC 3′ Primer R-2 111 5′ ATCCAACCGCAGGTTCCCCTAC 3′ R-3 112 5′ ATCCAGCCGCAGGTTCCCCTAC 3′

The primers shown in Table 11 were purified by HPLC (High Performance Liquid Chromatography) after synthesis. Three forward primers and three reverse primers were mixed and dissolved in a TE buffer solution such that each primer concentration had an ultimate concentration of 10 pmol/μl.

3. Extraction of Genome DNAs (Model Specimens) of Etiologic Agents [3-1] Microbial Culture & Preprocess for Genome DNA Extraction

First, microbial culture media were produced by culturing type strains of the etiologic agents (Staphylococcus aureus type strain (ATCC12600), Staphylococcus epidermidis type strain (ATCC14990), Escherichia coli type strain (ATCC11775), Klebsiella pneumoniae type strain (ATCC13883), Pseudomonas aeruginosa type strain (ATCC10145), Serratia marcescens strain, Streptococcus pneumoniae type strain, Haemophilus influenzaestrain, Enterobacter Cloacae type strain (ATCC13047), and Enterococcus faecalis type strain (ATCC19433)) in accordance with a conventional method. Each of the microbial culture media was sampled 1.0 ml (0D₆₀₀=0.7) into a 1.5-ml microtube. The cells were collected by centrifuge (8,500 rpm, 5 min, 4° C.). After the supernatant was removed, a 300-μl enzyme buffer (50 mM Tris-HCl: p.H. 8.0, 25 mM EDTA) was added, and the broth was re-suspended by using a mixer. From the re-suspended broth, the cells were collected again by centrifuge (8,500 rpm, 5 min, 4° C.). After the supernatant was removed, the following enzyme solution was added to the collected cells, and the broth was re-suspended by using the mixer.

Lysozyme 50 μl (20 mg/ml in Enzyme Buffer)

N-Acetylmuramidase SG 50 μl (0.2 mg/ml in Enzyme Buffer

The broth added with the enzyme solution and re-suspended was left stand still in an incubator at 37° C. for 30 min to melt cell walls.

[3-2] Genome Extraction

Microbial genome DNA extraction to be described below was done by using a nucleic acid purification kit (MagExtractor-Genome: available from TOYOBO).

More specifically, a 750-μl melting/absorption solution and a 40-μl magnetic beads were added to the preprocessed microbial suspension. The suspension was intensely stirred for 10 min by using a tube mixer (step 1).

Next, the microtube was set in a separation stand (Magical Trapper) and left stand still for 30 sec to gather magnetic particles to the wall surface of the tube. The supernatant was removed while the microtube was kept set in the stand (step 2).

Next, a 900-μl cleaning solution was added. The solution was re-suspended by stirring it for about 5 sec by a mixer (step 3).

The microtube was set in the separation stand (Magical Trapper) and left stand still for 30 sec to gather magnetic particles to the wall surface of the tube. The supernatant was removed while the microtube was kept set in the stand (step 4).

Steps 3 and 4 were repeated to execute the second cleaning process (step 5). After that, 900-μl 70% ethanol was added. The solution was re-suspended by stirring it for about 5 sec by a mixer (step 6).

The microtube was set in the separation stand (Magical Trapper) and left stand still for 30 sec to gather magnetic particles to the wall surface of the tube. The supernatant was removed while the microtube was kept set in the stand (step 7).

Steps 6 and 7 were repeated to execute the second cleaning process by using 70% ethanol (step 8). After that, 100-μl pure water was added to the collected magnetic particles. The solution was stirred for 10 min by a tube mixer (step 9).

The microtube was set in the separation stand (Magical Trapper) and left stand still for 30 sec to gather magnetic particles to the wall surface of the tube. The supernatant was collected to a new tube while the microtube was kept set in the stand.

[3-3] Test of Collected Genome DNAs

The collected genome DNAs of microorganisms (etiologic agent strain) underwent agarose electrophoresis and 260/280-nm absorbance determination in accordance with the conventional method so that the quality (the admixture amount of low molecular nucleic acid and the degree of decomposition) and collection amount were tested. In this embodiment, about 9 to 10-μg genome DNAs were collected in each bacterium. No degradation of genome DNAs or admixture of rRNA was observed. The collected genome DNAs were dissolved in a TE buffer solution at an ultimate concentration of 50 ng/μl and used in the following examples.

4. Preparation of DNA Microarray

The DNA Microarray was prepared according to Japanese Patent Application Laid-Open No. 11-187900.

[4-1] Cleaning of Glass Substrate

A glass substrate (size: 25 mm×75 mm×1 mm, available from Iiyama Tokushu Glass) made of synthetic silica was placed in a heat- and alkali-resisting rack and dipped in a cleaning solution for ultrasonic cleaning, which was prepared to a predetermined concentration. The glass substrate was kept dipped in the cleaning solution for a night and cleaned by ultrasonic cleaning for 20 min. The substrate was picked up, lightly rinsed by pure water, and cleaned by ultrasonic cleaning in ultrapure water for 20 min. The substrate was dipped in a 1N aqueous sodium hydroxide solution heated to 80° C. for 10 min. Pure water cleaning and ultrapure water cleaning were executed again. A silica glass substrate for a DNA microchip was thus prepared.

[4-2] Surface Treatment

A silane coupling agent KBM-603 (available from Shinetsu Silicone) was dissolved in pure water at a concentration of 1% and stirred at room temperature for 2 hrs. The cleaned glass substrate was dipped in the aqueous solution of the silane coupling agent and left stand still at room temperature for 20 min. The glass substrate was picked up. The surface was lightly rinsed by pure water and dried by spraying nitrogen gas to both surfaces of the substrate. The dried substrate was baked in an oven at 120° C. for 1 hr to complete the coupling agent treatment, thereby introducing an amino group to the substrate surface. Next, N-(6-Maleimidocaproyloxy)succinimido) (to be abbreviated as EMCS hereinafter) available from Dojindo Laboratories was dissolved in a 1:1 medium mixture of dimethyl sulfoxide and ethanol such that an ultimate concentration of 0.3 mg/ml was obtained, thereby preparing an EMCS solution.

The baked glass substrate was left stand and cooled and dipped in the prepared EMCS solution at room temperature for 2 hrs. With this process, the amino group introduced to the surface by the silane coupling agent reacted with the succinimide group in the EMCS to introduce the maleimide group to the surface of the glass substrate. The glass substrate picked up from the EMCS solution was cleaned by using the above-described medium mixture in which the EMCS was dissolved. The glass substrate was further cleaned by ethanol and dried in a nitrogen gas atmosphere.

[4-3] Probe DNA

The microorganism detection probe prepared in Example 1 was dissolved in pure water. The solution was dispensed such that the ultimate concentration (at ink dissolution) became 10 μM. Then, the solution was freeze-dried to remove water.

[4-4] DNA Discharge by BJ Printer and Bonding to Substrate

An aqueous solution containing 7.5-wt % glycerin, 7.5-wt % thioglycol, 7.5-wt % urea, and 1.0-wt % Acetylenol EH (available from Kawaken Fine Chemicals) was prepared. Each of the seven probes (Table 1) prepared in advance was dissolved in the medium mixture at a specific concentration. An ink tank for an inkjet printer (tradename: BJF-850, available from Canon) is filled with the resultant DNA solution and attached to the printhead.

The inkjet printer used here was modified in advance to allow printing on a flat plate. When the inkjet printer inputs a printing pattern in accordance with a predetermined file creation method, an about 5-picoliter DNA solution can be spotted at a pitch of about 120 μm.

The printing operation was executed for one glass substrate by using the modified inkjet printer, thereby preparing a DNA microarray. After confirming that printing was reliably executed, the glass substrate was left stand still in a humidified chamber for 30 min to make the maleimide group on the glass substrate surface react with the thiol group at the nucleic acid probe terminal.

[4-5] Cleaning

After reaction for 30 min, the DNA solution remaining on the surface was cleaned by using a 10-mM phosphate buffer (pH 7.0) containing 100-mM NaCl, thereby obtaining a gene chip (DNA microarray) in which single-stranded DNAs were immobilized on the glass substrate surface.

5. Amplification and Labeling of Specimens (PCR Amplification & Fluorescent Labeling)

Amplification of microbial genes as specimens and labeling reaction will be described below

Premix PCR reagent 25 μl  (TAKARA ExTaq) Template Genome DNA 2 μl (100 ng) Forward Primer mix 2 μl (20 pmol/tube each) Reverse Primer mix 2 μl (20 pmol/tube each) Cy-3 dUTP (1 mM) 2 μl (2 nmol/tube) H₂0 17 μl  Total 50 μl 

Amplification reaction of the reaction solution having the above composition was caused by using a commercially available thermal cycler in accordance with the following protocol.

95° C. 10 min. 92° C. 55° C.

72° C. 45 sec. 72° C. 10 min.

After the end of reaction, the primers were removed (purified) by using a purification column (QIAquick PCR Purification Kit available from QIAGEN). Then, determination of the amplified products was executed to obtain labeled specimens.

6. Hybridization

Detection reaction was performed by using the gene chips prepared by [4. Preparation of DNA Microarray] and the labeled specimen prepared by [5. Amplification and Labeling of Specimen (PCR Amplification & Fluorescent Labeling)].

[6-1] Blocking of DNA Microarrays

BSA (fetal bovine serum albumin, Fraction V: available from Sigma) was dissolved in a 100-mM NaCl/10-mM phosphate buffer such that a 1 wt % solution was obtained. The gene chips prepared by [4. Preparation of DNA Microarray] were dipped in the solution at room temperature for 2 hrs to execute blocking. After the end of blocking, the chips were cleaned by using a 2×SSC solution (NaCl 300 mM, Sodium Citrate (trisodium citrate dihydrate, C₆H₅Na₃.2H₂O) 30 mM, pH 7.0) containing 0.1-wt % SDS (Sodium Dodecyl Sulfate), rinsed by pure water, and hydro-extracted by a spin dryer.

[6-2] Hybridization

The hydro-extracted gene chips were set in a hybridization apparatus (Hybridization Station available from Genomic Solutions Inc). Hybridization reaction was caused in a hybridization solution under conditions to be described below.

[6-3] Hybridization Solution

6×SSPE/10% Form amide/Target (all 2nd PCR Products)

6×SSPE: NaCl 900 mM, NaH₂PO₄.H₂O 60 mM, EDTA 6 mM, pH, 7.4)

[6-4] Hybridization Conditions

65° C. 3 min

92° C. 2 min

45° C. 3 hrs

Wash 2×SSC/0.1% SDS at 25° C.

Wash 2×SSC at 20° C.

(Rinse with H₂O: Manual)

Spin dry (The hybridization reaction was caused at 65° C. for 3 min, at 92° C. for 2 min, and at 45° C. for 3 hrs. The gene chips were cleaned by using 2×SSC/0.1% SDS at 25° C. and 2×SSC at 20° C., rinsed by pure water, and spin-dried).

7. Microorganism Detection (Fluorometry)

The gene chips after the end of hybridization reaction were subjected to fluorometry by using a gene chip fluorescent detector (GenePix 4000B available from Axon). As a result, the respective bacteria could be detected with sufficient signals at a high reproducibility, as shown in Tables 12 to 21. No hybrid bodies for other bacteria were detected.

In this example, fluorometry was executed twice for each gene chip. The results are shown below.

TABLE 12 Staphylococcus aureus First Second SEQ. Fluores- Fluores- Probe ID. cence cence No. No. Sequence luminance S/N luminance S/N PA-1 1 5′ GAACCGCATGGTTCAAAAGTGAAAGA 3′ 3000 42.9 2900 40.8 PA-2 2 5′ CACTTATAGATGGATCCGCGCTGC 3′ 7700 110.0 7700 108.5 PA-3 3 5′ TGCACATCTTGACGGTACCTAATCAG 3′ 6400 91.4 6400 90.1 PA-4 4 5′ CCCCTTAGTGCTGCAGCTAACG 3′ 2500 35.7 2500 35.2 PA-5 5 5′ AATACAAAGGGCAGCGAAACCGC 3′ 7800 111.4 7800 109.9 PA-6 6 5′ CCGGTGGAGTAACCTTTTAGGAGCT 3′ 4800 68.6 4800 67.6 PA-7 7 5′ TAACCTTTTAGGAGCTAGCCGTCGA 3′ 4500 64.3 4300 60.6 PA-8 8 5′ TTTAGGAGCTAGCCGTCGAAGGT 3′ 4800 68.6 4800 67.6 PA-9 9 5′ TAGCCGTCGAAGGTGGGACAAAT 3′ 5300 75.7 5200 73.2

TABLE 13 Staphylococcus epidermidis First Second SEQ. Fluores- Fluores- Probe ID. cence cence No. No. Sequence luminance S/N luminance S/N PB-1 15 5′ GAACAGACGAGGAGCTTGCTCC 3′ 1000 14.5 1100 15.7 PB-2 16 5′ TAGTGAAAGACGGTTTTGCTGTCACT 3′ 1800 26.1 1800 25.7 PB-3 17 5′ TAAGTAACTATGCACGTCTTGACGGT 3′ 1400 20.3 1400 20 PB-4 18 5′ GACCCCTCTAGAGATAGAGTTTTCCC 3′ 1000 14.5 1100 15.7 PB-5 19 5′ AGTAACCATTTGGAGCTAGCCGTC 3′ 1800 26.1 2000 28.6 PB-6 20 5′ GAGCTTGCTCCTCTGACGTTAGC 3′ 1200 17.4 1300 18.6 PB-7 21 5′ AGCCGGTGGAGTAACCATTTGG 3′ 1100 15.9 1100 15.7

TABLE 14 Escherichia coli First Second SEQ. Fluores- Fluores- Probe ID. cence cence No. No. Sequence luminance S/N luminance S/N PC-1 25 5′ CTCTTGCCATCGGATGTGCCCA 3′ 1200 17.6 1200 17.9 PC-2 26 5′ ATACCTTTGCTCATTGACGTTACCCG 3′ 1500 22.1 1600 23.9 PC-3 27 5′ TTTGCTCATTGACGTTACCCGCAG 3′ 1100 16.2 1200 17.9 PC-4 28 5′ ACTGGCAAGCTTGAGTCTCGTAGA 3′ 2000 29.4 2100 31.3 PC-5 29 5′ ATACAAAGAGAAGCGACCTCGCG 3′ 1500 22.1 1500 22.4 PC-6 30 5′ CGGACCTCATAAAGTGCGTCGTAGT 3′ 2400 35.3 2600 38.8 PC-7 31 5′ GCGGGGAGGAAGGGAGTAAAGTTAAT 3′ 1200 17.6 1200 17.9

TABLE 15 Klebsiella pneumoniae First Second SEQ. Fluores- Fluores- Probe ID. cence cence No. No. Sequence luminance S/N luminance S/N PD-1 37 5′ TAGCACAGAGAGCTTGCTCTCGG 3′ 500 7.6 600 9 PD-2 38 5′ TCATGCCATCAGATGTGCCCAGA 3′ 600 9.1 600 9 PD-3 39 5′ CGGGGAGGAAGGCGATAAGGTTAAT 3′ 700 10.6 700 10.4 PD-4 40 5′ TTCGATTGACGTTACCCGCAGAAGA 3′ 1000 15.2 1200 17.9 PD-5 41 5′ GGTCTGTCAAGTCGGATGTGAAATCC 3′ 2700 40.9 2700 40.3 PD-6 42 5′ GCAGGCTAGAGTCTTGTAGAGGGG 3′ 3400 51.5 3300 49.3

TABLE 16 Pseudomonas aeruginosa First Second SEQ. Fluores- Fluores- Probe ID. cence cence No. No. Sequence luminance S/N luminance S/N PE-1 48 5′ TGAGGGAGAAAGTGGGGGATCTTC 3′ 3500 50.0 3600 50 PE-2 49 5′ TCAGATGAGCCTAGGTCGGATTAGC 3′ 1600 22.9 1400 19.4 PE-3 50 5′ GAGCTAGAGTACGGTAGAGGGTGG 3′ 3500 50.0 3400 47.2 PE-4 51 5′ GTACGGTAGAGGGTGGTGGAATTT 3′ 3100 44.3 3100 43.1 PE-5 52 5′ GACCACCTGGACTGATACTGACAC 3′ 1600 22.9 1600 22.2 PE-6 53 5′ TGGCCTTGACATGCTGAGAACTTTC 3′ 1200 17.1 1200 16.7 PE-7 54 5′ TTAGTTACCAGCACCTCGGGTGG 3′ 1000 14.3 1200 16.7 PE-8 55 5′ TAGTCTAACCGCAAGGGGGACG 3′ 1100 15.7 1100 15.3

TABLE 17 Serratia marcescens First Second SEQ. Fluores- Fluores- Probe ID. cence cence No. No. Sequence luminance S/N luminance S/N PF-1 58 5′ TAGCACAGGGAGCTTGCTCCCT 3′ 600 8.8 600 8.7 PF-2 59 5′ AGGTGGTGAGCTTAATACGCTCATC 3′ 700 10.3 600 8.7 PF-3 60 5′ TCATCAATTGACGTTACTCGCAGAAG 3′ 2000 29.4 2200 31.9 PF-4 61 5′ ACTGCATTTGAAACTGGCAAGCTAGA 3′ 2800 41.2 2700 39.1 PF-5 62 5′ TTATCCTTTGTTGCAGCTTCGGCC 3′ 700 10.3 700 10.1 PF-6 63 5′ ACTTTCAGCGAGGAGGAAGGTGG 3′ 3400 50.0 3300 47.8

TABLE 18 Streptococcus pneumoniae First Second SEQ. Fluores- Fluores- Probe ID. cence cence No. No. Sequence luminance S/N luminance S/N PG-1 69 5′ AGTAGAACGCTGAAGGAGGAGCTTG 3′ 1000 14.9 1100 16.2 PG-2 70 5′ CTTGCATCACTACCAGATGGACCTG 3′ 1200 17.9 1300 19.1 PG-3 71 5′ TGAGAGTGGAAAGTTCACACTGTGAC 3′ 1000 14.9 1100 16.2 PG-4 72 5′ GCTGTGGCTTAACCATAGTAGGCTTT 3′ 1800 26.9 1900 27.9 PG-5 73 5′ AAGCGGCTCTCTGGCTTGTAACT 3′ 1300 19.4 1500 22.1 PG-6 74 5′ TAGACCCTTTCCGGGGTTTAGTGC 3′ 1300 19.4 1300 19.1 PG-7 75 5′ GACGGCAAGCTAATCTCTTAAAGCCA 3′ 2000 29.9 2100 30.9

TABLE 19 Haemophilus influenzae First Second SEQ. Fluores- Fluores- Probe ID. cence cence No. No. Sequence luminance S/N luminance S/N PH-1 78 5′ GCTTGGGAATCTGGCTTATGGAGG 3′ 3500 50.0 3600 50 PH-2 79 5′ TGCCATAGGATGAGCCCAAGTGG 3′ 600 8.8 700 10.1 PH-3 80 5′ CTTGGGAATGTACTGACGCTCATGTG 3′ 600 8.8 600 8.7 PH-4 81 5′ GGATTGGGCTTAGAGCTTGGTGC 3′ 1100 16.2 1200 17.4 PH-5 82 5′ TACAGAGGGAAGCGAAGCTGCG 3′ 700 10.3 600 8.7 PH-6 83 5′ GGCGTTTACCACGGTATGATTCATGA 3′ 1300 19.1 1300 18.8 PH-7 84 5′ AATGCCTACCAAGCCTGCGATCT 3′ 2100 30.9 2200 31.9 PH-8 85 5′ TATCGGAAGATGAAAGTGCGGGACT 3′ 700 10.3 600 8.7

TABLE 20 Enterobacter cloacae First Second SEQ. Fluores- Fluores- Probe ID. cence cence No. No. Sequence luminance S/N luminance S/N PI-1 86 5′ CAGAGAGCTTGCTCTCGGGTGA 3′ 2100 29.2 2200 .31 PI-2 87 5′ GGGAGGAAGGTGTTGTGGTTAATAAC 3′ 7900 109.7 7900 111.3 PI-3 88 5′ GGTGTTGTGGTTAATAACCACAGCAA 3′ 1000 13.9 1300 18.3 PI-4 89 5′ GCGGTCTGTCAAGTCGGATGTG 3′ 6400 88.9 6400 90.1 PI-5 90 5′ ATTCGAAACTGGCAGGCTAGAGTCT 3′ 9400 130.6 9200 129.6 PI-6 91 5′ TAACCACAGCAATTGACGTTACCCG 3′ 4700 65.3 4800 67.6 PI-7 92 5′ GCAATTGACGTTACCCGCAGAAGA 3′ 4600 63.9 4500 63.6

TABLE 21 Enterococcus faecalis First Second SEQ. Fluo- Fluo- Probe ID. rescence rescence No. No. Sequence luminance S/N luminance S/N PJ-1 98 5′TTCTTTCCTCCCGAGTGCTTGCA 3′ 1500 22.1 1500 20.8 PJ-2 99 5′AACACGTGGGTAACCTACCCATCAG 3′ 2400 35.3 2700 37.5 PJ-3 100 5′ATGGCATAAGAGTGAAAGGCGCGTT 3′ 5600 82.4 5600 77.8 PJ-4 101 5′GACCCGCGGTGCATTAGCTAGT 3′ 2300 33.8 2300 31.9 PJ-5 102 5′GGACGTTAGTAACTGAACGTCCCCT 3′ 1000 14.7 1400 19.4 PJ-6 103 5′CTCAACCGGGGAGGGTCATTGG 3′ 4400 64.7 4400 61.1 PJ-7 104 5′TTGGAGGGTTTCCGCCCTTCAG 3′ 1700 25   1800 25  

The numerical values of florescent luminances (photomultiplier voltage: 400 V) in Tables 12 to 21 indicate average pixel luminances (resolution: 5 μm). The S/N ratios indicate values obtained by dividing the fluorescent luminances by background average values measured by analysis software (GenePix Pro Ver.3.0 available from Axon) attached to the measuring device.

As is apparent from Tables 12 to 21, the respective etiologic agents can be detected with sufficient signals at a high reproducibility.

Example 2 Microorganism Detection Using 2-Step PCR

As in Example 1, probe DNAs, specimen amplification PCR primers, the genome DNAs of etiologic agents, and DNA microarrays were prepared, and the following experiments were conducted.

1. Amplification and Labeling of Specimens (PCR Amplification & Fluorescent Labeling)

Amplification of microbial genes as specimens (1st PCR) and labeling (2nd PCR) reaction will be described below.

2. Amplification Reaction Solution Composition: 1st PCR

Premix PCR reagent (TAKARA 25 μl ExTaq)

Template Genome DNA 2 μl (10 ng) Forward Primer mix 2 μl (20 pmol/tube each) Reverse Primer mix 2 μl (20 pmol/tube each) H₂0 19 μl  Total 50 μl 

Amplification reaction of the reaction solution having the above composition was caused by using a commercially available thermal cycler in accordance with the following protocol.

95° C. 10 min. 92° C. 55° C.

72° C. 45 sec. 72° C. 10 min.

After the end of reaction, purification was performed by using a purification column (QIAquick PCR Purification Kit available from QIAGEN). Then, determination of the amplified products was executed.

3. Labeling Reaction Solution Composition: 2nd PCR Enzyme

(QIAGEN Hotstar Taq  0.5 μl (2.5 u) Polymerase) Template DNA (1st PCR Product)   10 μl (30 ng) dNTP mix (Low dTTP)*   2 μl Cy-3 dUTP (1 mM)   2 μl (2 nmol/tube) Reverse Primer mix   5 μl (50 pmol/tube each) 10 × Buffer   5 μl H₂0 25.5 μl Total   50 μl *dNTP mix (Low dTTP): dATP, dCTP, dGTP/5 mM(final: 10 nmol/tube) dTTP/4 mM (final: 8 nmol/tube)

Amplification reaction of the reaction solution having the above composition was caused by using a commercially available thermal cycler in accordance with the following protocol.

95° C. 10 min. 92° C. 55° C.

72° C. 45 sec. 72° C. 10 min.

After the end of reaction, purification was performed by using a purification column (QIAquick PCR Purification Kit available from QIAGEN) to obtain labeled specimens.

4. Hybridization

Hybridization was done in accordance with the same procedures as in Example 1.

5. Microorganism Detection (Fluorometry)

Fluorometry was executed for the DNA microarrays after the end of hybridization reaction by using a DNA microarray fluorescent detector (GenePix 4000B available from Axon). Tables 22 to 31 show the measurement results.

Even in this example, fluorometry was executed twice for each DNA microarray. The results are shown in Tables 22 to 31.

TABLE 22 Staphylococcus aureus First Second SEQ. Fluo- Fluo- Probe ID. rescence rescence No. No. Sequence luminance S/N luminance S/N PA-1 1 5′ GAACCGCATGGTTCAAAAGTGAAAGA 3′ 14000 186.7 13000 173.3 PA-2 2 5′ CACTTATAGATGGATCCGCGCTGC 3′ 36000 480   35000 466.7 PA-3 3 5′ TGCACATCTTGACGGTACCTAATCAG 3′ 31000 413.3 29000 386.7 PA-4 4 5′ CCCCTTAGTGCTGCAGCTAACG 3′ 10000 133.3 10000 133.3 PA-5 5 5′ AATACAAAGGGCAGCGAAACCGC 3′ 39000 520   38500 513.3 PA-6 6 5′ CCGGTGGAGTAACCTTTTAGGAGCT 3′ 22000 293.3 22100 294.7 PA-7 7 5′ TAACCTTTTAGGAGCTAGCCGTCGA 3′ 22000 293.3 21800 290.7 PA-8 8 5′ TTTAGGAGCTAGCCGTCGAAGGT 3′ 25000 333.3 24000 320   PA-9 9 5′ TAGCCGTCGAAGGTGGGACAAAT 3′ 26000 346.7 25500 340  

TABLE 23 Staphylococcus epidermidis First Second SEQ. Fluo- Fluo- Probe ID. rescence rescence No. No. Sequence luminance S/N luminance S/N PB-1 15 5′ GAACAGACGAGGAGCTTGCTCC 3′ 4500  62.5 4700  67.1 PB-2 16 5′ TAGTGAAAGACGGTTTTGCTGTCACT 3′ 9000 125   8900 127.1 PB-3 17 5′ TAAGTAACTATGCACGTCTTGACGGT 3′ 7100  98.6 7300 104.3 PB-4 18 5′ GACCCCTCTAGAGATAGAGTTTTCCC 3′ 4800  66.7 5200  74.3 PB-5 19 5′ AGTAACCATTTGGAGCTAGCCGTC 3′ 9100 126.4 9300 132.9 PB-6 20 5′ GAGCTTGCTCCTCTGACGTTAGC 3′ 5800  80.6 6300 90  PB-7 21 5′ AGCCGGTGGAGTAACCATTTGG 3′ 5400 75  5500  78.6

TABLE 24 Escherichia coli First Second SEQ. Fluo- Fluo- Probe ID. rescence rescence No. No. Sequence luminance S/N luminance S/N PC-1 25 5′ CTCTTGCCATCGGATGTGCCCA 3′  5600  76.7  6200  83.8 PC-2 26 5′ ATACCTTTGCTCATTGACGTTACCCG 3′  7600 104.1  7500 101.4 PC-3 27 5′ TTTGCTCATTGACGTTACCCGCAG 3′  5600  76.7  5700 77  PC-4 28 5′ ACTGGCAAGCTTGAGTCTCGTAGA 3′  9400 128.8  9300 125.7 PC-5 29 5′ ATACAAAGAGAAGCGACCTCGCG 3′  7200  98.6  7200  97.3 PC-6 30 5′ CGGACCTCATAAAGTGCGTCGTAGT 3′ 11500 157.5 11500 155.4 PC-7 31 5′ GCGGGGAGGAAGGGAGTAAAGTTAAT 3′  5600  76.7  5500  74.3

TABLE 25 Klebsiella pneumoniae First Second SEQ. Fluo- Fluo- Probe ID. rescence rescence No. No. Sequence luminance S/N luminance S/N PD-1 37 5′ TAGCACAGAGAGCTTGCTCTCGG 3′  2000  28.6  2100 30  PD-2 38 5′ TCATGCCATCAGATGTGCCCAGA 3′  2500  35.7  2600  37.1 PD-3 39 5′ CGGGGAGGAAGGCGATAAGGTTAAT 3′  2900  41.4  2900  41.4 PD-4 40 5′ TTCGATTGACGTTACCCGCAGAAGA 3′  4500  64.3  4700  67.1 PD-5 41 5′ GGTCTGTCAAGTCGGATGTGAAATCC 3′  9900 141.4 10100 144.3 PD-6 42 5′ GCAGGCTAGAGTCTTGTAGAGGGG 3′ 13000 185.7 13400 191.4

TABLE 26 Pseudomonas aeruginosa First Second SEQ. Fluo- Fluo- Probe ID. rescence rescence No. No. Sequence luminance S/N luminance S/N PE-1 48 5′ TGAGGGAGAAAGTGGGGGATCTTC 3′ 17000 239.4 17300 240.3 PE-2 49 5′ TCAGATGAGCCTAGGTCGGATTAGC 3′  8300 116.9  8600 119.4 PE-3 50 5′ GAGCTAGAGTACGGTAGAGGGTGG 3′ 17400 245.1 17000 236.1 PE-4 51 5′ GTACGGTAGAGGGTGGTGGAATTTC 3′ 15000 211.3 16000 222.2 PE-5 52 5′ GACCACCTGGACTGATACTGACAC 3′  8000 112.7  8300 115.3 PE-6 53 5′ TGGCCTTGACATGCTGAGAACTTC 3′  5400  76.1  5800  80.6 PE-7 54 5′ TTAGTTACCAGCACCTCGGGTGG 3′  5300  74.6  5100  70.8 PE-8 55 5′ TAGTCTAACCGCAAGGGGGACG 3′  5400  76.1  5000  69.4

TABLE 27 Serratia marcescens First Second SEQ. Fluo- Fluo- Probe ID. rescence rescence No. No. Sequence luminance S/N luminance S/N PF-1 58 5′ TAGCACAGGGAGCTTGCTCCCT 3′  3100  43.7  3300  45.2 PF-2 59 5′ AGGTGGTGAGCTTAATACGCTCATC 3′  3300  46.5  3200  43.8 PF-3 60 5′ TCATCAATTGACGTTACTCGCAGAAG 3′ 10100 142.3 10000 137   PF-4 61 5′ ACTGCATTTGAAACTGGCAAGCTAGA 3′ 12000 169   11800 161.6 PF-5 62 5′ TTATCCTTTGTTGCAGCTTCGGCC 3′  4100  57.7  4200  57.5 PF-6 63 5′ ACTTTCAGCGAGGAGGAAGGTGG 3′ 14300 201.4 14300 195.9

TABLE 28 Streptococcus pneumoniae First Second SEQ. Fluo- Fluo- Probe ID. rescence rescence No. No. Sequence luminance S/N luminance S/N PG-1 69 5′ AGTAGAACGCTGAAGGAGGAGCTTG 3′  4500  63.4 4300  60.6 PG-2 70 5′ CTTGCATCACTACCAGATGGACCTG 3′  5800  81.7 5600  78.9 PG-3 71 5′ TGAGAGTGGAAAGTTCACACTGTGAC 3′  5000  70.4 4900 69  PG-4 72 5′ GCTGTGGCTTAACCATAGTAGGCTTT 3′  8700 122.5 8800 123.9 PG-5 73 5′ AAGCGGCTCTCTGGCTTGTAACT 3′  7200 101.4 7300 102.8 PG-6 74 5′ TAGACCCTTTCCGGGGTTTAGTGC 3′  6700  94.4 7000  98.6 PG-7 75 5′ GACGGCAAGCTAATCTCTTAAAGCCA 3′ 10200 143.7 9900 139.4

TABLE 29 Haemophilus influenzae First Second SEQ. Fluo- Fluo- Probe ID. rescence rescence No. No. Sequence luminance S/N luminance S/N PH-1 78 5′GCTTGGGAATCTGGCTTATGGAGG 3′  3100  44.3  3200  45.1 PH-2 79 5′TGCCATAGGATGAGCCCAAGTGG 3′  3200  45.7  3200  45.1 PH-3 80 5′CTTGGGAATGTACTGACGCTCATGTG 3′  4900 70   3600  78.9 PH-4 81 5′GGATTGGGCTTAGAGCTTGGTGC 3′  3900  55.7  3800  53.5 PH-5 82 5′TACAGAGGGAAGCGAAGCTGCG 3′  6700  95.7  6500  91.5 PH-6 83 5′GGCGTTTACCACGGTATGATTCATGA 3′ 10200 145.7 11000 154.9 PH-7 84 5′AATGCCTACCAAGCCTGCGATCT 3′  4200 60   4100  57.7 PH-8 85 5′TATCGGAAGATGAAAGTGCGGGACT 3′  3200  45.7  3500  49.3

TABLE 30 Enterobacter cloacae First Second SEQ. Fluo- Fluo- Probe ID. rescence rescence No. No. Sequence luminance S/N luminance S/N PI-1 86 5′ CAGAGAGCTTGCTCTCGGGTGA 3′ 10000 133.3  9900 133.8 PI-2 87 5′GGGAGGAAGGTGTTGTGGTTAATAAC 3′ 38000 506.7 38000 513.5 PI-3 88 5′GGTGTTGTGGTTAATAACCACAGCAA 3′  4700  62.7  4700  63.5 PI-4 89 5′GCGGTCTGTCAAGTCGGATGTG 3′ 31000 413.3 32000 432.4 PI-5 90 5′ATTCGAAACTGGCAGGCTAGAGTCT 3′ 47500 633.3 45000 608.1 PI-6 91 5′TAACCACAGCAATTGACGTTACCCG 3′ 23600 314.7 24000 324.3 PI-7 92 5′GCAATTGACGTTACCCGCAGAAGA 3′ 21500 286.7 22700 306.8

TABLE 31 Enterococcus faecalis First Second SEQ. Fluo- Fluo- Probe ID. rescence rescence No. No. Sequence luminance S/N luminance S/N PJ-1 98 5′TTCTTTCCTCCCGAGTGCTTGCA 3′  7000  98.6  7300 101.4 PJ-2 99 5′AACACGTGGGTAACCTACCCATCAG 3′ 12300 173.2 12000 166.7 PJ-3 100 5′ATGGCATAAGAGTGAAAGGCGGCTT 3′ 25000 352.1 27400 380.6 PJ-4 101 5′GACCCGCGGTGCATTAGCTAGT 3′ 10000 140.8 11000 152.8 PJ-5 102 5′GGACGTTAGTAACTGAACGTCCCCT 3′  5600  78.9  5200  72.2 PJ-6 103 5′CTCAACCGGGGAGGGTCATTGG 3′ 22100 311.3 22200 308.3 PJ-7 104 5′TTGGAGGGTTTCCGCCCTTCAG 3′  8800 123.9  9000 125  

The numerical values of florescent luminances (photomultiplier voltage: 400 V) in Tables 22 to 31 indicate average pixel luminances (resolution: 5 μm). The S/N ratios indicate values obtained by dividing the fluorescent luminances by background average values measured by analysis software (GenePix Pro Ver.3.0 available from Axon) attached to the measuring device.

As is apparent from Tables 22 to 31, the respective etiologic agents can be detected with sufficient signals at a high reproducibility.

Example 3 Microorganism Detection Using 2-Step PCR

As in Examples 1 and 2, probe DNAs, specimen amplification PCR primers, the genome DNAs of etiologic agents, and DNA microarrays were prepared, and the following experiments were conducted.

1. Amplification and Labeling of Specimens (Utilization of PCR Amplification with Fluorescent Labeling)

Amplification of microbial genes as specimens (1st PCR) and labeling (2nd PCR) reaction will be described below.

2. Amplification Reaction Solution Composition: 1st PCR

AmpliTaq Gold LD(5U/μL) 0.5 μL Template DNA variable dNTP mis(2.5 mM/each) 4.0 μL ×10 PCR buffer 5.0 μL 25 mM MgCl₂ 7.0 μL Forward Primer 0.25 μL  Mix(10 μM/each) Reverse Primer 0.25 μL  Mix(10 μM/each) H₂O variable Total  50 μL

Amplification reaction of the reaction solution having the above composition was caused by using a commercially available thermal cycler in accordance with the following protocol.

95° C. 10 min. 92° C. 67° C.

72° C. 45 sec. 72° C. 10 min.

After the end of reaction, purification was performed by using a purification column (QIAquick PCR Purification Kit available from QIAGEN). Then, determination of the amplified products was executed.

3. Labeling Reaction Composition: 2nd PCR

Premix PCR reagent(TAKARA 25 μl ExTaq) Template DNA (1st PCR Product) Variable (30 ng/tube) Cy3 Labeled Reverse primer Mix  5 μl H₂0 Variable Total 50 μl

Amplification reaction of the reaction solution having the above composition was caused by using a commercially available thermal cycler in accordance with the following protocol.

95° C. 10 min. 92° C. 65° C.

72° C. 45 sec. 72° C. 10 min.

After the end of reaction, purification was performed by using a purification column (QIAquick PCR Purification Kit available from QIAGEN) to obtain labeled specimens.

4. Hybridization

Hybridization was done in accordance with the same procedures as in Example 1.

5. Microorganism Detection (Fluorometry)

Fluorometry was executed for the DNA microarrays after the end of hybridization reaction by using a DNA microarray fluorescent detector (GenePix 4000B available from Axon). Tables 32 to 41 show the measurement results.

Note that, in this example, fluorometry was executed once twice for each DNA microarray. The results are shown in Tables 32 to 41.

TABLE 32 Staphylococcus aureus First Second SEQ. Fluo- Fluo- Probe ID. rescence rescence No. No. Sequence luminance S/N luminance S/N PA-10 10 5′ ACGGACGAGAAGCTTGCTTCTCT 3′   247   3.4   146   2.1 PA-11 11 5′ TGTCACTTATAGATGGATCCGCGCT 3′  4177  57.9  3083  43.4 PA-12 12 5′ TGTAAGTAACTGTGCACATCTTGACG 3′  4686  64.9  3768  53.1 PA-13 13 5′ ACAACTCTAGAGATAGAGCCTTCCCC 3′  2612  36.2  2709  38.2 PA-14 14 5′ GTGGAGTAACCTTTTAGGAGCTAGCC 3′ 26505 367.2 17560 247.3

TABLE 33 Staphylococcus epidermidis First Second SEQ. Fluo- Fluo- Probe ID. rescence rescence No. No. Sequence luminance S/N luminance S/N PB-2 16 5′ TAGTGAAAGACGGTTTTGCTGTCACT 3′  7000  94.1  1800  25.7 PB-4 18 5′ GACCCCTCTAGAGATAGAGTTTTCCC 3′  3274  44.0  1100  15.7 PB-8 22 5′ AGACGAGGAGCTTGCTCCTCTG 3′   111   1.5   59   0.8 PB-9 23 5′ AGAACAAATGTGTAAGTAACTATGCACGT 3′  6920  93.0  4910  70.1 Pb-10 24 5′ ACCATTTGGAGCTAGCCGTCGA 3′ 15244 205.0 18136 259.1

TABLE 34 Escherichia coli First Second SEQ. Fluo- Fluo- Probe ID. rescence rescence No. No. Sequence luminance S/N luminance S/N PC-4 28 5′ ACTGGCAAGCTTGAGTCTCGTAGA 3′ 5416 74.7 2100 31.3 PC-8 32 5′ TAACAGGAAGAAGCTTGCTTCTTTGCTG 3′  160  2.2  112  1.7 PC-9 33 5′ TTGCCATCGGATGTGCCCAGAT 3′ 4133 57.0 4581 68.4 PC-10 34 5′ GGAAGGGAGTAAAGTTAATACCTTTGCTC 3′ 4194 57.8 5349 79.8 PC-11 35 5′ ATCTTTTGTTGCCAGCGGTCCG 3′ 6719 92.7 2594 38.7 PC-12 36 5′ AAGGGAGTAAAGTTAATACCTTTGCTCATTG 3′ 3984 58.6 4021 60.0

TABLE 35 Klebsiella pneumoniae First Second SEQ. Fluo- Fluo- Probe ID. rescence rescence No. No. Sequence luminance S/N luminance S/N PD-7 43 5′ TCATGCCATCAGATGTGCCCAGAT 3′  5414 40.0 4171 62.3 PD-8 44 5′ CGGGGAGGAAGGCGATAAGGTTAA 3′  4096 30.2 6227 93.0 PD-9 45 5′ TTATCGATTGACGTTACCCGCAGAAGA 3′  4122 30.4 3269 48.8 PD-10 46 5′ CATTCGAAACTGGCAGGCTAGAGTC 3′  9474 70.0 6486 96.9 PD-11 47 5′ CCTTTGTTGCCAGCGGTTAGGC 3′ 10648 78.6 2754 41.1

TABLE 36 Pseudomonas aeruginosa First Second SEQ. Fluo- Fluo- Probe ID. rescence rescence No. No. Sequence luminance S/N luminance S/N PE-1 48 5′ TGAGGGAGAAAGTGGGGGATCTTC 3′ 6175  82.2 3600  50.0 PE-6 53 5′ TGGCCTTGACATGCTGAGAACTTTC 3′ 8159 108.6 1200  16.7 PE-7 54 5′ TTAGTTACCAGCACCTCGGGTGG 3′ 3277  43.6 1200  16.7 PE-8 55 5′ TGCATCCAAAACTACTGAGCTAGAGTAC 3′ 6626  88.2 7432 103.4 PE-9 56 5′ GTCGACTAGCCGTTGGGATCCT 3′ 5734  76.3 3365  46.8

TABLE 37 Serratia marcescens First Second SEQ. Fluo- Fluo- Probe ID. rescence rescence  No. No. Sequence luminance S/N luminance S/N PF-7 64 5′ GGTAGCACAGGGGAGCTTGCTC 3′  4482  66.4 1040 15.1 PF-8 65 5′ CGAGGAGGAAGGTGGTGAGCTTAATA 3′  6362  94.2 3199 46.3 PF-9 66 5′ TACGCTCATCAATTGACGTTACTCGC 3′  4569  67.7 2884 41.8 PF-10 67 5′ GAAACTGGCAAGCTAGAGTCTCGTAGA 3′  7905 117.1 6786 98.3 PF-11 68 5′ TTATCCTTTGTTGCCAGCGGTTCG 3′ 12787 189.4 4849 55.7

TABLE 38 Streptococcus pneumoniae First Second SEQ. Fluo- Fluo- Probe ID. rescence rescence No. No. Sequence luminance S/N luminance S/N PG-1 69 5′ AGTAGAACGCTGAAGGAGGAGCTTG 3′ 10078 70.3 1100  16.2 PG-5 73 5′ AAGCGGCTCTCTGGCTTGTAACT 3′  4331 30.2 1500  22.1 PG-6 74 5′ TAGACCCTTTCCGGGGTTTAGTGC 3′  4730 33.0 1300  19.1 PG-8 76 5′ GACATTTGCTTAAAAGGTGCACTTGCA 3′  7128 49.7 7720 113.6 PG-9 77 5′ GTTGTAAGAGAAGAACGAGTGTGAGAGTG 3′  6665 46.5 3297  48.5

TABLE 39 Haemophilus influenzae First Second SEQ. Fluo- Fluo- Probe ID. rescence rescence No. No. Sequence luminance S/N luminance S/N PH-1 78 5′ GCTTGGGAATCTGGCTTATGGAGG 3′ 11106 150.3 3600 50.0 PH-2 79 5′ TGCCATAGGATGAGCCCAAGTGG 3′  7056  95.5  700 10.1 PH-4 81 5′ GGATTGGGCTTAGAGCTTGGTGC 3′   100   1.4 1200 17.4 PH-5 82 5′ TACAGAGGGAAGCGAAGCTGCG 3′ 11237 152.1  600  8.7 PH-7 84 5′ AATGCCTACCAAGCCTGCGATCT 3′  5054  68.4 2200 31.9

TABLE 40 Enterobacter cloacae First Second SEQ. Fluo- Fluo- Probe ID. rescence rescence No. No. Sequence luminance S/N luminance S/N PI-8 93 5′ GTAGCACAGAGAGCTTGCTCTCG 3′ 2221  30.1  582  8.2 PI-9 94 5′ CGGGGAGGAAGGTGTTGTGGTTA 3′ 5484  74.2 2193 30.9 PI-10 95 5′ ACCACAGCAATTGACGTTACCCG 3′ 3325  45.0  646  9.1 PI-11 96 5′ GAAACTGGCAGGCTAGAGTCTTGTAG 3′ 7574 102.5 3039 42.8 PI-12 97 5′ AGGCGGTCTGTCAAGTCGGATG 3′ 5768  78.0 5701 80.3

TABLE 41 Enterococcus faecalis First Second SEQ. Fluo- Fluo- Probe ID. rescence rescence No. No. Fluorescence luminance S/N luminance S/N PJ-1 98 5′ TTCTTTCCTCCCGAGTGCTTGCA 3′ 1012 14.9 1500 20.8 PJ-3 100 5′ ATGGCATAAGAGTGAAAGGCGCTT 3′ 4266 62.6 5600 77.8 PJ-5 102 5′ GGACGTTAGTAACTGAACGTCCCCT 3′ 652 9.6 1400 19.4 PJ-8 105 5′ ATAGAGCTTTCCCTTCGGGGACAAA 3′ 3232 47.5 810 11.2 PJ-9 106 5′ CGAGGTCATGCAAATCTCTTAAAGCTTCT 3′ 11411 167.6 18776 260.7

As is apparent from Tables 32 to 41, the respective etiologic agents can be detected with sufficient signals at a high reproducibility.

As described above, according to the examples, an infectious etiologic agent can be identified by using microarrays on which probe sets capable of detecting the 10 bacteria, i.e., Staphylococcus aureus, Staphylococcus epidermidis, Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Serratia marcescens, Streptococcus pneumoniae, Haemophilus influenzae, Enterobacter cloacae, and Enterococcus faecalis are separately immobilized or combined. Hence, the problems of the DNA probe of microbial origin are solved. More specifically, because of the small number of bases, oligonucleotide probes can chemically be mass-produced, and purification and concentration control are possible. In addition, a probe set can be provided, which allows to detect bacteria in the same species all together and discriminatingly detect bacteria in other species for the purpose of classifying the bacteria depending on the species.

Furthermore, a probe set can be provided, which also considers the stability of a hybrid body between a probe and a specimen so that the difference between the species can accurately be evaluated on a DNA microarray. A carrier on which the probe DNAs are immobilized to make the probe DNAs react with specimens can also be provided. Also, a carrier can be provided, on which the probe DNAs are chemically immobilized so that the probe DNAs are stably immobilized on the carrier, and a detection result with high reproducibility can be obtained in the process of reaction between a specimen solution and the probes and probe sets.

According to the above examples, 16s rRNA gene arrangements in the genes of infectious etiologic agents can be detected in proper quantities. Hence, the presence of an infectious etiologic agent can efficiently and accurately be determined.

Example 4 Primer Set

The primer sets (Table 11) used in the above examples to amplify the 16s rRNA gene arrangements of one or some of Staphylococcus aureus, Staphylococcus epidermidis, Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Serratia marcescens, Streptococcus pneumoniae, Haemophilus influenzae, Enterobacter cloacae, and Enterococcus faecalis will be described.

The primer sets of this example are designed to give a satisfactory amplification result in PCR reaction executed to identify an infectious etiologic agent. “Satisfactory” means not only that the target 16s rRNAs are sufficiently amplified but also that no products other than the 16s rRNAs are generated.

“Satisfactory” also means that only the 16s rRNAs of an infectious etiologic agent are amplified without amplifying human genome genes originated in a specimen, which are contained in the specimen.

Any specimen in which bacteria may be present, and for example, body fluids originated in animals such as human and livestock, including blood, spinal fluid, phlegm, stomach fluid, vaginal discharge, and intraoral mucus, and excretion such as urine and feces are used in this example. All media which can be contaminated by bacteria can also be used in this example, including food, drink water and hot spring water in the natulal environment, which may cause food poisoning by contamination, filters from air and water cleaners, and so forth. Animals and plants which should be quarantined in import/export are also used as specimens.

The PCR reaction used in this example includes PCR reaction which uses an extracted nucleic acid itself as a template, asymmetrical PCR reaction which uses primers on one side of SEQ ID Nos. 107 to 109 (F1 to F3 in Table 11) or SEQ ID Nos. 110 to 112 (R1 to R3 in Table 11), and PCR which executes labeling for visualization.

1. Preparation of Specimen Amplification PCR Primers

As 16s rRNA gene (target gene) amplification PCR primers for etiologic agent detection, nucleic acid sequences shown in Table 11 were designed.

More specifically, probe sets which specifically amplify the genome parts coding the 16s rRNAs, i.e., primers for which the specific melting points were made uniform as much as possible at the two end portions of the 16s rRNA coding region of a base length of 1,500 were designed. In order to simultaneously amplify variants or a plurality of 16s rRNA coding regions on genomes, a plurality of kinds of primers were designed.

The primers shown in Table 11 were purified by HPLC (High Performance Liquid Chromatography) after synthesis. All of three forward primers and three reverse primers were mixed and dissolved in a TE buffer solution such that each primer concentration had an ultimate concentration of 10 pmol/μl. In this example, all the forward primers and reverse primers were used. Alternatively, one to three forward primers and one to three reverse primers may be used.

By using a thus prepared solution of forward primers and reverse primers (forward primer mix and reverse primer mix), genome DNAs extracted by the method described in [3. Extraction of Genome DNAs (Model Specimens) of Etiologic Agents] were amplified by the method described in [5. Amplification and Labeling of Specimens (PCR Amplification & Fluorescent Labeling)].

After the end of reaction, the primers were removed by using a purification column (QIAquick PCR Purification Kit available from QIAGEN). Then, the amplified products were examined by gel electrophoresis. One band was detected in 1,500 base pair regions, and it was confirmed that satisfactory PCR reaction was executed. No byproducts were generated.

When the primers shown in Table 11 were used, satisfactory PCR amplification results were obtained in, e.g., all of the above-described 10 infectious etiologic agents (Staphylococcus aureus, Staphylococcus epidermidis, Escherichia Coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Serratia marcescens, Streptococcus pneumoniae, Haemophilus influenzae, Enterobacter cloacae, and Enterococcus faecalis).

Example 5 Amplification of 16s rRNA Genes from Mixture of Blood and Broth

Bacteremia model systems were prepared by adding 10³, 10⁴, and 10⁵ Enterobacter cloacae, which was cultured in accordance with the procedures described in Example 1, to 200-μl human blood (collected EDTA blood). An N-acetyl muramidase solution (0.2 mg/ml in Enzyme Buffer) was added to each solution. The solutions were heated to 37° C. for 30 min. After that, DNAs were extracted by using Qiamp Blood mini Kit (available from QIAGEN) to prepare templates for PCR reaction.

PCR reaction was caused for these DNAs by using the primers shown in Table 11, as in Example 4.

As a result, as in Example 4, one band was detected in 1,500 base pair regions, and it was confirmed that satisfactory PCR reaction was executed. No byproducts were generated. The amount of PCR amplified products obtained from the band was proportional to the added cell amount. This indicates that when the primer sets were used, only the 16s rRNAs of Enterobacter cloacae were amplified without generating any PCR byproduct of human genome.

As described above, according to this example, the 16s rRNA parts in the genes of a plurality of kinds of infectious etiologic agents can efficiently be amplified at a high purity. In addition, even when human genome DNAs are present, only the 16s rRNAs of an infectious etiologic agent can efficiently be amplified.

As has been described above, according to the present invention, an infection detection probe which allows mass preparation at a time and identification of a species in similar species can be provided. More specifically, an infection detection probe which can suitably be used to classify a plurality of kinds of etiologic agents of an infection on the basis of the species can be provided.

Alternatively, an infection detection probe suitable for detection of, e.g., the above-described 10 bacteria as the etiologic agents of infections can be provided.

A probe set can also be provided, which also considers the stability of a hybrid body between an infection detection probe and a specimen so that the difference between similar species can accurately be evaluated on a DNA chip.

In addition, a carrier on which the infection detection probe is immobilized to make the infection detection probe react with the specimen can be provided.

Furthermore, a carrier can be provided, on which the infection detection probes are chemically immobilized so that the infection detection probes are stably immobilized on the carrier, and a detection result with high reproducibility can be obtained in the process of reaction with a specimen solution.

According to the present invention, there is also provided a PCR reaction primer which amplifies the 16s rRNAs of an etiologic agent in a specimen in order to detect and/or identify an infectious etiologic agent.

According to the present invention, there is also provided a primer set which can commonly be used for a plurality of species and effectively amplify the 16s rRNAs of an etiologic agent even when the species is unknown.

According to the present invention, there is also provided a primer set which can amplify the 16s rRNAs of a plurality of kinds of etiologic agents under the same PCR conditions.

As many apparently widely different embodiments of the present invention can be made without departing from the spirit and scope thereof, it is to be understood that the invention is not limited to the specific embodiments thereof except as defined in the appended claims. 

1. A probe set of infection detection probes each of which can detect an existence of a 16s rRNA gene originating in Staphylococcus aureus in a sample in which one or more of Staphylococcus aureus, Staphylococcus epidermidis, Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Serratia marcescens, Streptococcus pneumoniae, Haemophilus influenzae, Enterobacter cloacae and Enterococcus faecalis possibly exists, wherein the probe set comprises nine oligonucleotides, each consisting of a different one of the following base sequences (A) to (I): (A) SEQ ID No. 1 or the complementary sequence thereof; (B) SEQ ID No. 2 or the complementary sequence thereof; (C) SEQ ID No. 3 or the complementary sequence thereof; (D) SEQ ID No. 4 or the complementary sequence thereof; (E) SEQ ID No. 5 or the complementary sequence thereof; (F) SEQ ID No. 6 or the complementary sequence thereof; (G) SEQ ID No. 7 or the complementary sequence thereof; (H) SEQ ID No. 8 or the complementary sequence thereof; and (I) SEQ ID No. 9 or the complementary sequence thereof.
 2. A probe set which can detect an existence of a 16s rRNA gene originating in Staphylococcus aureus, the probe set consisting of different types of oligonucleotides, wherein the different types of oligonucleotides consist of nine oligonucleotides, each consisting of a different one of the following base sequences (A) to (I): (A) SEQ ID No. 1 or the complementary sequence thereof; (B) SEQ ID No. 2 or the complementary sequence thereof; (C) SEQ ID No. 3 or the complementary sequence thereof; (D) SEQ ID No. 4 or the complementary sequence thereof; (E) SEQ ID No. 5 or the complementary sequence thereof; (F) SEQ ID No. 6 or the complementary sequence thereof; (G) SEQ ID No. 7 or the complementary sequence thereof; (H) SEQ ID No. 8 or the complementary sequence thereof; and (I) SEQ ID No. 9 or the complementary sequence thereof.
 3. A carrier on which the probe set according to claim 1 or 2 is chemically immobilized.
 4. A method of detecting a gene originating in Staphylococcus aureus in a specimen in which bacteria may be present comprising reacting the carrier of claim 3 with the specimen and detecting the gene originating in Staphylococcus aureus based on hybridization of the probe set on the carrier with the specimen.
 5. The probe set according to claim 1, wherein the probe set comprises fourteen oligonucleotides, each consisting of a different one of the following base sequences (A) to (N): (A) SEQ ID No. 1 or the complementary sequence thereof; (B) SEQ ID No. 2 or the complementary sequence thereof; (C) SEQ ID No. 3 or the complementary sequence thereof; (D) SEQ ID No. 4 or the complementary sequence thereof; (E) SEQ ID No. 5 or the complementary sequence thereof; (F) SEQ ID No. 6 or the complementary sequence thereof; (G) SEQ ID No. 7 or the complementary sequence thereof; (H) SEQ ID No. 8 or the complementary sequence thereof; (I) SEQ ID No. 9 or the complementary sequence thereof (J) SEQ ID No. 10 or the complementary sequence thereof; (K) SEQ ID No. 11 or the complementary sequence thereof; (L) SEQ ID No. 12 or the complementary sequence thereof; (M) SEQ ID No. 13 or the complementary sequence thereof; and (N) SEQ ID No. 14 or the complementary sequence thereof.
 6. An array on which the probe set according to claim 1 is immobilized, wherein the probe set includes the only probes on the array for detecting Staphylococcus aureus. 